Battery Indicator Pro shows your battery charge level (percent) as an icon in your status bar, with temperature, health, voltage, and time since plugged / unplugged in the notification area. Now has an alarm feature.

Features:
• Fully configurable green, amber, red, and black icons
• Icon plugins
• Estimated charge / discharge time left
• Battery logging. You can log the battery state (charge, status, voltage, temperature) and browse the logs on the phone or export to CSV.
• Manually or automatically disable / reenable device lock screen / lockscreen / keyguard
• Alarms (full, charge above X, charge below X, temperature above X, or health failure)
• Themes for main window
• Lots of configurability; most features are optional
• Very lightweight (please email me if you think otherwise, and I’ll help you figure out what’s wrong — I promise this app will not drain your battery.)
• Now shows 1% increments even on most Motorola devices (option needs to be enabled on devices that default to 10% increments)
• Open source

A one-time purchase now gets you free installs and updates for life on all your Android devices (phones, tablets, etc.)

Limitations:
• It’s not possible to replace the built-in battery icon

All requested app permissions are explained on the project website.

* Please see the project website (linked to below) to contact me if you have any questions or problems — I can’t respond to comments left here. *